In vitro chemosensitivity testing of squamous cell carcinoma of the head and neck. A preliminary report.

: This study deals with in vitro chemosensitivity testing of squamous cell carcinoma of the head and neck by measuring the drug-induced inhibition of [3H]thymidine incorporation. Cell suspensions and tumour slices obtained from four human tumour xenografts were used. These were grown in nude mice and tested in this animal for their sensitivity to bleomycin and cis-platinum. No reliable data could be obtained with the use of cell suspensions because of the rapid decrease in cell viability during incubation. The incubation of 400-microns-thick tumour slices using hyperbaric O2 revealed a stable control level of [3H]thymidine incorporation which persisted for more than 24 h. Cytotoxic drugs only demonstrated a significant and reproducible decrease in the incorporation of [3H]thymidine in those tumours which were found to be sensitive to these drugs in nude mice. This technique seems to be very promising but needs further evaluation of its application on tumour specimens obtained directly from patients.